Apparatus for drilling under water



Oct. 21, 1952 ,c. H. CARLISLE 1 4 APPARATUS FOR DRILLING UNDER WATER Fild Jan. 29, 1949 2 SHEETS-SHEET 1 FIG. I.

Charles H. Carlisle, INVEIITOR.

Oct. 21, 1952 c. H. CARLISLE' APPARATUS FOR DRILLING UNDER WATER 2 SHEETSvSHBET 2 Filed Jan. 29, 1949 Gear Box Cable Protector Charles H. Oar/isle, IN V INTOR AGENT.

Patented Oct. 21, 1952 APPARATUS FQR DRILLING UNDER WATER Charles H. Carlisle, Houston, Tex., assignonby mesne. assignments, to Standard Oil Development Company, Elizabeth, N. J., a corporation of Delaware Application January 29, 1949, Serial No. 73,507 r 4 Claims.

The presentv invention is directed to apparatus for drilling in the earth. More particularly, the invention is directed to apparatus and a method useful in seismic prospecting and for placing charges of explosive in the earth beneath a body of water. H i J In conventional seismic prospecting on dry land it is common practice to drill a shot hole of desired depth in the earth, to place a suit-' able charge of dynamite or similar explosive in the shot hole, and to fire the chargeof explosive in order to create an artificial seismic disturbance from which useful measurements may be made. The problems involved in drilling and loading the shoe hole are relatively simple and have been; solved by employing either a hand operated or a power driven rotary bit to produce the shot hole. Except in sandy regions where the shot hole may tend to cave in if it is not cased, thereis generally no difiiculty in loadingthe explosive into the hole, it being usually sufiicient to lower the charge into the hole or to push it downward through mud remaining in the hgle by means of a pole or similar device. i

However, when seismic prospecting is conducted over water covered areas, and particularly over areas submerged toa depth in excess of about-ten or twenty feet beneath the surface of the water, the problems involved in placing shots or charges of explosive are greatly inupon the body of water interferes with the drilling. operation. Furthermore, after a shot hole has'been drilled under water, it is often difiicult to find the hole and place the charge of explosive therein. I have now devised a simple and novel apparatus for solving the aboveproblems which may be utilized to advantage not only in deep water, that is, in water exceeding about ten feet in depth, but also in relatively shallow water or in marshy areas.

In accordance with my invention, 1 provide a boat, barge or other suitable vehicle having a.

hoisting mechanism such as a winch and derrick boom carrying a hoisting cable. tremity of the hoisting cable, I provide a housing which is adapted to stand on or adjacent the floor of the body of water, either fully or partly submerged depending upon the depth of the water. Thehousing is flexibly connected to the hoisting means and is' arranged to be held against rotation with'respect to the floor of the body of water.

At the free ex- .a charge of explosive in Carried by the housingis'a suitable motor and a torque transmission means mechanically, coupled to a drill stem adapted to be rotated thereby. In one embodiment of the apparatus of my invention, the housing is slidably mounted in a supporting frame so that the housing may move substantially vertically .with respect to the floor of the body of water but will notrotate with respect thereto. be journaled in the housing, may be caused to rotate and advance downwardly into the earth.

detonator and explosive. The separable connection betweenthe bitand the drill stem is so con-f structed and arranged that the bit may be rotated into the earth by the drill stem and the latter m y] then be separated'from the bit leaving the bit and explosive buried in the earth while retrieve ing the free end of the cap line. I

The apparatus and method of my, invention may be better understood from the following de--'' scription, read in conjunction with'fthe accompanying drawing in which: i T I Fig. 1 is a schematic elevation View, partly'in section,,showing the general arrangement of com! ponents of my apparatus when drilling or placing the earth beneath a body of water; I a

Fig. 2 is a longitudinal section view of a preferred bit and a part of a drill s'tem in accord-- ance with my invention; M v Fig. 3 is an elevation view, partly in section,

of a housing, motor, and gear case adaptedto be used in the practice of my invention;

Fig. 4 is an elevation View, partly in section, of a second embodiment of a housing, motor, and 1 gear case adapted to be used in accordance with my invention;

'1 Fig. 5 is an elevation view, partly in sectiori of I a swivel adapted to be usedwith the embodiment of Fig. 4 and.

used with the embodimentshown in Fig.4.

In Fig. l of the drawing,- the numeral I designates earth structu're defining the floor or bottom of a body of waterhaving an upper surface 2; Floating upon the, surface of the water is;a boat or barge 3 which preferably may be self-propelled, Mounted in any suitable and convenient mannen on boat 3 is-a hoisting means which may include i a hoistingboom 4, a winch 5, and a hoisting'cable Thus the drill stem, which may Fig. 6 is a pictorial view with parts cut away showing a preferred drill stem which may be 3 8. The cable 5 is at least of sufiicient length to reach to theb'ottom of the water when arranged for raising and"loweringinto the watera frame member, designated generally by the numeral I. In the drawing, frame member 1 is illustrated as having legs 8 and top and bottoni bracesf9 and l0, respectively. It is to be understood, however, that frame I may be of any desiredand suitable construction so long as the requirem'ents'of portability, reasonable strength and rigidity, and ability to hold firmly against rotation on the floor of the body of water are met. Mounted rigidly- .in frame 1 and substantially perpendicular to the base thereof are a plurality of track or guide "members ll adaptedto guide a housing [2 for vertical'motion 'without permitting rotary motion thereofwithresp'ect to-flo'or l.

I Guide members I l .areprovided, adjacent their uppefand lower extremities; with suitable stops topreventvertical movementof housing I 2 above orbelow thefconfinesof frame 1. Hoi'stingcable: 6 is preferably attached directly to housing 12 ratherthan to frame; 1' so that theformer may" bepulledupward-within the latter. Theafore mentioned-stops should; accordingly, be sufficiently' strong; so" that hoisting of housing 12 against the" upper stops"'will also permit hoisting offf'ramef'l. It will; be apparent; howeventhat' separate hoisting means may be provided for. framed; or the hoistingcable" may be attached AS will be described more fully" with respect to Figure}, housing I 2'' carries a suitable motor;

preferably? power transmission. gears; and bearthe free ends, adaptedto be'taken aboardboat 3, are outermost and capable-of'uncoiling freely. Whena gentle pull isapplied' in an'upWard dire'c' tion, generally alongthe longitudinal axisof bit H. After insertion of bobbin 28 within cavity irig'sin' which are journaledi a drill stem i3; At"

the'lower'endiof drill stem I3- is a: bit;'referred tozgenerally by the numeral I L. As will be more fully expla'ined in connection with Figure 2, bit

may contain a charge of explosive a detonator, .and a cap line? which may be connected. to

' conventional means ('not'shown'), arranged on boat 3'; for; firing the detonator and explosive.

, ma'pr'eferred embodiment: ofmy invention, the

aforementioned cap line: is'pref'erably connected throughc'onductors within drill stem l 3' and slip rings 'ji'n housing. I2 to anexternal. cap line [5 whichmay be reeled aboard the boat '3 by conventional" means, not shown.

The motor within housing l.2,may beof'any 1 suitable typesuchyas a compressed. gas. driven turbina'anhydraulic mot'onj an electric motor or the like. Becausev of its compactness; lip-referto employ; aidirect current electric; motor. In any case; the motor maybe supplied. with energy through a power conduit: l'fifwhi'chmay lie-reeled aboardboat' 3 and' may be connected to a source ofi'power'm'ounte'd'thereon.

"'Turningnow' to Figure 2, the bit,v designated generally by thenumeral I4, is preferably so constructed and" arrangedthat; by rotation thereof '4 tional blasting cap or detonator 26 for the explosive.

which may be connected to conventional electrical means controllable. from boat 3 for firing the detonator andexplosive. Conductors 21 are preferably of'suitable length to extend from beneath the floor I to :above the surface 2 of the body of water. The length of the conductors 21 may conveniently be coiled on a spool or bobbin 28 which is placed within cavity 24 after loading explosive 25 and detonator- 26 therein. Conductors21 are wound upon bobbin 28 'in a manner suchthat the ends thereof which are connected todetonator 26 are innermost'on the bobbin" and 24', it is preferably fastened for retention therein as by inserting a wire pin or similar means 29 through openings 30 in diametrically opposite sides of' body member 22 and through openings 3! provided in the lower end'of' bobbin 28. Itwill be seen that'means 29 retainsnotonl'y b'obbin 28 but also explosive charge 2'5and' detonator 26 within cavity 24.

As'mentioned hereinbefore; myinvention' con'--- templates rotating bit 14 into the 'earthand there separating the bit'from'd'rill stem l3"; To.

accomplish this objective, bit lfmay'be' screw threadedly engaged in'suita'blemanner upon'the lower" end of drill stem [3. Howeverpto insure trouble-free separation of the bit'from the drill stem and to reduce the cost of construction, 1-

prefer to makethe lower end of drill stem I3" have a sliding fit into the upper end of'tubular in aparticularj direction about its longitudinal I axis while in contact with the earth, it will be drawn ;or forced downwardtherein. In a prefrred formfbit l4 may be madeup" of a solid,. cylindrical nose member'20 having a conical tip' 2l and attibular body"member 22" welded' or otherwiserigidly' aihxed thereto. Around nose member? are one'or more helical'fins 23 arranged somewhatin the form of a screw thread adapted'tmpulrbit- M i'n'to-the-earth when it is rotated. Tubular body member22l defines a-cavitys 241 in which may be placed a suitable charge of iexplosive -fi such as dynamite, and a-conven'-- bit body 22.

be seen that slots 35, dog members 361 and'shear pin 32lform a longitudinally slidable, keyed tool joint which cooperates on the loweren'd of the drill stem and upper end ofthe bit to hold the bitaiilxed: to the drill stem when these-elements are rotated and moved into the earth and alsopermits separation of'the bit'from the'drill stem when the latter'is pulled from the earth leaving the bit in the earth.

As will be seen from Fig; 2 of thedrawihggdrill stem I3 may be a tubular element. The extreme lower end of the tubular elementmay' be'closed with a tightly fitting plug 31 made of electrical insulating. material retained rigidly in place" by" any suitable means. Passing through plug 31 substantiallyparallel with the axis of the drill stem are two or more electrical terminals 38 Within drill stem I3, terminals 38- are" permanentlyconnected to apair of insulated'leads 39 running up through the-drill sternv to slip-rings which will be described in connection withFigure 3. The protruding outer ends of terminals 38 are connected to cap line'Z-T. As a safetyprecaution, terminals 38may be short-circuitedwith' a short loop' of wire- 40- which normally hangs Connected to blasting; cap 26;: in con- H yentional manner is a pair of i'nsulated'conduc- I tors 21 constituting at least a part of a cap line So that bit l4 will remain on drill stem I3 when the apparatus is lowered into the downward into cavity 24 of bit 'I4. A pin 4I1 may be passed through diametrically opposite holes in the walls of tubular body 22 and through the safety loop 40. Thus,.when the bit is driven into the earth and the drill stem pulled out of the bit, loop 40' will be automatically broken, thereby breaking the safety shunt.

Referring now to Fig. 3, the housing, designated generally by the numeral I2, may provide a water-tight compartment 42 for th motor 43 which, for purposes of description, will be assumed to be an electric motor. If the motor 43 is, in itself, water proof or adapted to operate when submerged in water, compartment 42 need.

not necessarily be water tight. Power conduit I6, for supplying power tomotor 43,1may be brought through the walls of compartment ll. by any suitable water-tight bushing.

Below compartment 42 is a second compartment 44 containing gears orother torque transmission means for transmitting the rotary motion of the motor drive shaft to a shaft 45 journaled in bearings 46 arranged in a compartment 41. Since housing I2 is adapted to be submerged beneath a body of water, it will be apparent that compartments 44 and 41 should preferably be made water tight to exclude access of water to the gears and bearings housed therein.

Arranged below compartment 41 is another. water-tight compartment 48 in which are arranged suitable brushes cooperating with slip rings mounted upon shaft 45 for rotatably bringing out'electrical connections from cap line conductors 39 to cap line I5. As will be seen from Fig. 3 of the drawing, the upper wall of compartment 48 may be defined by a flange member 49 which may support one of the bearings 45. Attached to, and depending from, flange 49 is a cylindrical member 50 in which a plurality of contact brushes are mounted in insulating bushings 52. The insulated conductors of cap line I5 may be brought into compartment 48 through a suitable water-tight joint arranged either in flange 49 or in the walls of housing I2, as desired, and are electrically connected to brushes 5|. Secured to shaft 45 within chamber 48 is an insulated support member to which are aflixed slip rings 54 which make electrical contact with brushes 5|. A passage provided in the lower end of shaft 45 permits the insulated conductors of cap line 39 to be brought into compartment 48 and be electrically connected to slip rings 54. The entrance to passage 55 at the lower end of shaft 45 is preferably made Water tight, as by means of a suitable bushing 56, after cap line 39 has been introduced therein.

As will be seen from Figure 3, shaft 45 extends through the lower wall of housing I2 through a water-tight gland 51. Drill stem I3 may be affixed rigidly to shaft 45 by screw threads 58 or by other suitable means.

From the description of Figures 1, 2 and 3 it may be seen that, when it is desired to place acharge of explosive in the earth beneath a body of water in accordance with my invention a charge of explosive 25, a detonator 26, and a coiled cap line 21 are loaded into bit I4. line 2! is then electrically connected to terminals 38, together with shunt 40, if used, and bit I4 is slid onto the end of drill stem I3 and is fastened in place with shear pin 32. Frame 7 together with housing I2, drill stem 53 and bit I4 may then be lowered by means of hoisting cable 6 until the frame rests upon the earth beneath the water in a selected location. Since drill Cap 4 stem I3 is ofa chosen length such that bit l4 will protrudeonly slightly through the bottom of sion on cable 6 is slackened. Motor 43 within housing I2 may next be set in operation by sup- 3 plying power through conduit I5, and drill stem I3 and bit I4 are thereby caused to rotate. '-By v allowing tension on cable IE to remain slack, bit' I3 may be drawn into the earth until housing l2 reaches the lower stops on guide rails II.. At

this time, motor 43 must be stopped,either manually or by automatic means not shown in the drawing. A strong upward pull applied to cable 6 will then cause shear pin 32 to break and effect separation of drill stem I3 from bit I4.

I2 within frame 1 and will ultimately raise the frame off the bottom. As drill stem I3 is pulled away from the bit, cap line '27 will uncoil from bobbin 28, thereby providing continuouselectrical connection from detonator 26 to means above:

the surface of the water so that the explosive charge may be fired after the. boat 3 and frame.

l have been moved to a safe distance from the shot hole.

Since the depth of the shot hole produced by the apparatus heretofore described in conjunction with Figures 1, 2 and 3 will be limitedby the length of drill stem I3 which, in turn, may be limited by the height of frame I, it may be desirable under some conditions to employ an,

embodiment of apparatus .such as is shown in Figs. l, 5, and 6.

In the embodiment of Fig. 4, the numeral BB designates generally a housing adapted. to .be.

submerged under water and be placed upon ,or adjacent the floor of the body of water.

to exclude access of water to components arranged therein. As distinguished from thehousing I2 described in the embodiment of Figures 1 and 3, housing 68 is preferably arranged to be placed directly upon the bottom of the body of water without support of the frame 7 of Figure 1. Housing 66 is preferably provided on the externalbottom thereof with a plurality of rigid leg members liI of a length sufficient to hold U the housing slightly above the bottom of the body of water and permit the bit to contact. said bottom. Leg members El are, desirably, in the I I form of vertically disposed fins adapted to hold;

housing 6i] against rotation with respect to the bottom of the body of water. i

Extending vertically through, and preferably coaxially within, housing 60 is a tubular shaft 62. Shaft 62 is journaled for rotation about its axis in housing 50 by means of, bearings 63, and

water may be excluded from entry into housing 50 along the shaft by suitable packing glands 84. Keyed, 'or otherwise suitably afiixed, externallyto shaft 62 within housing 60 is a bull gear 65., One or more motors 66, which may be ofthe types described with respect to Fig. 3 are rigidly;

mounted upon suitable supports within housing 60 and are mechanically connected for rotation of bull gear 65 and shaft 62 through gear train or other torque transmission means 81. H An elongated tubular drill stem, designated generally by the numeral 68, passes coaxially through the tubular bore of shaft 62, and is keyed or otherwiseheld against rotation with respect Continned upward pull on cable 6 will raise housing..-

.Ac-' cordingly, housing 64 is preferably watertight,

7 thereto, as-ibyifkeysz 'G Ba-t and; 6911-:- amxed: to shaft;

62;:- operating; inkey-waytwI in drill stem: B812 Whiledrillistem: .68"mayuno't rotatezwith. respectto"- shaft 62", it is axially sli'dablewwith' respect"- thereto by: virtue offlkey-wayr 10a'extending..sub-' stantiallyxthroughout.the length of drill stem '68:

It .will ..be .understood that although. drill stem 68-: 'has-lbeen assumedto be circular in cross sec tioniand tO 1bB keyed tofshaftliladrill stem' 68 mayibe no'n-circular in cross-section and. the in neiibore ofshaftfiz may be of: similar cro'ss'sec tioh' tor permitthe drill stem: to slidetaxiallyi butnot toc rotate therein; so that drill stem 68- will not mov zout :ofshaft 6-2,;the former may; be'

provided with: stop. members Na and 'Hbaf--' fixed,..respectively,x.atthe upper and lower end thereof;

Amxedrto'therilower endaof. dr-ill: stem 68;.as: byzixscrew threads: l2- and. 12a; or other suitablemeans; is aswiv'el-jcint (see Figure 5) the outer body of. which is designated .by'i' the I numeral 13. Arranged'c'oaxially within" body: 13' and supported bytath'rust bearing 14 and needle bearing. 15 is a hollow-swivelmemberr'lfii Packing, gland 11 in the -upper-end of body 13- permits swivel member.

16toarotate: within body 13 without permitting;

water to' .enter therein.

Passingllconcentrically through. drill stem 68 and swivel member 16 and clamped to the latter" by clamping means" isza' steel sheathed hoistinghcable ficontaining insulated cap line con-- ductors 15 Below clamping means 18 and" secured'rto .swivel member 16:. is an insulated cy-- lindrical member 19,.carrying' slip rings 88 to.

which conductors/l5. are electrically connected. Concentrically arranged aroundmember 19 is: a member 8|, secured to body 13'; carrying insulated brushes 82 which cooperate withv slip rings-80..

As will be seen fromvthe showing in Figure 5', the lower end' of swivel body 13 is. preferably constructedhsimilar tothe lower end of drill toreceive bit ll. Thus,.the lower end of swivel body=13 may be'provided-with dogs and withpassage adapted-L to receive shear pinSZL It' mayalso'beprovided-with insulated plug 31 hav-- ing electtical terminals 38 Conductors 39 electrically'connect terminals 38 to brushes 82'. It will be -understood that the" entire swivel. as-

sembly;'-including 'the pointof entry of cable 6 therein is'preferably made waterproof by-anyf' suitable "means to'prevent entry of waterinto' I Sincedetails of suitable water' proofing. means will be apparent 'to' a; skilledmechanic'; they are' not the swivel bearings and slip rings.

fully described herein. F'r'omthe foregoing description; it may be observed that the operation of the embodiment of FigS.=4-and 5 is'slightly different from, but basicallly 'similar'to', the operationfof th'e embodiment described in" connection with Figs. 1, 2 and 3.

Thus; referring-"111 part to'Figs. 1 and 2 and in art-re Figs. 4 "and 5-,' the housing arm be loweredfrom boat 3 on ca'ble 6-, extending stem 'I3 i-llustrated-in Fig.2 so that it is adapted members tl rest" upon the' bottom ofthejibody'f of water and explosive laden bit [4 is in contact with said bottom. Tension on cable 'B is'suitably 'sla'ck'ene'd-and motor'fi fi is placed in oper-- ation causing bull ge'ar' fifii shaft 62; drillstem 68 an'dbit' l4- on the end th'ereof to rotate. Bit

Wisthereby' moved downward into the earth aiid drill'stem 58 Slides axially downward-in shaft ifi' imtil upper' stop-"1 I 0; contacts shaft 62', whereupon further 'rotatio'nfof: the drill stem will tend tocause-"bit T4 to pulloff of the drill stem; 'Oper-'=' ation ofmotor 66 may then be stopped manuallyi or'by automatic meansilnot shown) and drill stem SB-maybe pulled out of bit I4= byope'ration Continued operation ofthe hoisting means will notonly separate the of hoisting. means 5:

drill stem ir'cm the bit but also will permit the raisingof housinglGO ofi of the bottom of thewater a's described in" conjunction with= Figs 1.- Boat 3 and-housing .sn'may then be mov'ed to 'a'. safe distance from the shot hole;-whereupon.theexplosive may: be fi-redby. an electric current.-

passed through conductors-152.391. and 21'. I

The embodiment of apparatus shown in Figs:-

4-and 5 has advantages over that shownin-Figsl- 1-'-*3' in that it is less bulky and the depth of shot' hole is not limited to' a convenient size' of supporting frame;v Nevertheless, the depth? of placement l ofithe explosive charge which may be placed withthe embodiment of apparatus shown:

in Figs 4 and S-is-limite'd by the length of drill stem. which may be'conveniently employed;

Accordingly, it may be: preferred to replace the single length of drillstem. Baby a telescopic drill stem 's'u'chas is shown in Fig.6 so that charges.v

of explosivemay be placed at greater depths;

In Fig. 6', theLnu'm'eral 9fl designates anouter tubular member adapted. to replace tubular member 1 68? shown: inFig; 4-. Arrangedv longitu dinally throughout the length of member is a key-way 91 adapted to receive the keys 69a and; 69b sh0wn iniliig'rl. Similar tothe embodiment shown inFig. 4, member 90 isprovidedwithstops- 'Hwand: H b: which may beintheformof narrow collars aflixed: circ'umferentiall-y around member" 90 at the extremities thereof.; Affixed concert-- trically within member 90; as'byspotwelding att numerouspoints, and extending throughout itslen'gthis a second tubular-member 92'. Tubular mernber S2 -is sl'otted longitudinally throughout the greater part of its lengthto providean iii-- ternal key-way or chann'el'93 adapted to receiveake'yi'or splin'e 94? The lower end of key-way 93-is blocked by a' 'sto'p 95 adapted' to preventkey Key 9'4is secured to" a thirdtub-ular member 96 adjacent the upper end thereof and member 96 is adaptedito" slidetelesco'pically within me'ni ber' 92. Secured circumferentially' aroundth'e lower'extremity'Iof member 96 isa collar 91 formin'g'iastop to prevent member'B G from-passing. upwardly out of member. 92. 'Secured concen trically within member 96 as by spot-welding, is i a fourth tubular member 98 which, similar to member 92; is slotted-longitudinally throughout-rthegreater-partotits length to provide a second internal key-way or-wchannel 99- adapted to receive key or spline l00., Channel-'99 is blocked..

atits lower end by a stop llll which may be-a part of member 98; adapted toprevent key I00 from'passing downward outof channel99.

98'. Collar 94" from" passing" downward and out of channel 9 From the foregoing description it will be apparent that the device of Figure 6 provides a drill stem comprising a plurality of tubular members 'telescoped one within another in a manner such that each succeeding internal member is axially slidable within, but not rotatable with respect to the next succeeding external member. Although the device of Fig. 6 has been described in accordance with a convenient manner of fab ricating it, it will be understood that pairs of tubular members 90-92, and 96-98 may each be single tubular members provided with suitable splines and grooves adapted to provide axial slidabilitywith respect to one another. It will also be understood that, although three members have been described as capable of being telescoped one within another, a greater or less number may be so arranged. The lengths of members 90, 96, and I02 may be chosen according to convenience in handling the assembled drill stem and according to the desired depth of drill hole.

As in the embodiment of Fig. 4, the hoisting cable 6 is passed axially through the elements 90, 96 and I02 of Fig. 6 and is attached to swivel member 16. Thus, when the telescopic drill stem is employed, rotation thereof, with bit 14 arranged on the lower end of swivel l3 and the latter afixed upon the lower end of the drill stem, causes the bit to advance downward into the earth and this,in turn, causes successive sections of the drill stem to be extended. Keys 94 and I contact stops 95 and till, respectively, and upper stop H a contacts shaft 62 at the extreme extension of the drill stem. Further rotation of the drill stem and bit tends to cause the latter to pull oil. When rotation of the drill stem is stopped and an upward pull is applied to cable 6', the swivel body is pulled away from the bit, and the drill stem is caused to telescope until stops I03 and 9'! contact the lower ends of members 96 and 90, respectively, and lower stop 'Hb contacts the lower end of shaft 62 whereupon housing 60 and its contents are raised above the earth.

- While my invention has been described with particular reference to means for placing charges of explosive in shot holes particularly for seismic prospecting purposes, it is apparent that the invention is also applicable to the placement of charges beneath the surface of a body of water for other purposes.

Having fully described the apparatus of my invention and a, preferred mode of operating it, what I claim as new and desire to secure by Letters Patent is:

1. Apparatus for placing a charge of explosive in the earth beneath a body of water comprising a bit member defining a cavity therein closed at its lower end and adapted to retain a charge of explosive, a drill stem adapted to advance said bit member into the earth, and means including a longitudinally slidable joint cooperating on adjacent ends of the bit member and drill stem adapted to release the former from the latter during withdrawal of the drill stem from the earth.

2. Apparatus for placing a charge of explosive in the earth beneath a body of water comprising a rotary bit defining a cavity therein closed at its lower end and adapted to retain a charge of explosive, means secured around the exterior of said bit for fastening the latter into the earth by rotation thereof, a drill stem adapted to rotate said bit. and means including a longitudinal- 1y keyed Joint cooperating on adjacent ends of the bit and drill stem for releasing the former from the latter during withdrawal of the drill stem from the earth.

3. Apparatus for placing a charge of explosive in the earth beneath a body of water comprising, in combination, a bit defining a cavity therein closed at its lower end and adapted to retain a charge of explosive and a detonator, means secured around the exterior of said bit for pulling the latter into the earth by rotation thereof, a drill stem capable of rotating said bit in the earth, means including a longitudinally slidable keyed joint cooperating on the lower end of said drill stem and upper end of said bit constructed and arranged to hold said bit affixed to said drill stem when the bit and drill stem are rotated and moved into the earth and to effect separation of the bit from the drill stem when the latter is pulled from the earth, driving means above and connected to said drill stem for rotating the latter, and means for pulling said drill stem from the earth.

4. Apparatus for placing a charge of explosive in the earth in seismic exploration under water covered areas comprising, in combination, a bit defining a cavity therein adapted to retain a charge of explosive and a detonator for said explosive, a helical blade secured around the exterior of said bit for drawing the latter into the earth by rotation of the bit, a tubular drill stem having a longitudinal passage therethrough, insulated electrical terminals aflixed in the lower end of said drill stem, insulated conductors passing through said longitudinal passage and electrically connecting said terminals to means adapted to fire said detonator, a tool joint including longitudinally keyed means cooperating on the lower end of said drill stem and the upper end of said bit adapted to affix the bit rigidly to the drill stem while the bit and drill stem are rotated and moved into the earth and to efiect separation of the bit from the drill stem as the latter is pulled from the earth, a pair of insulated conductors electrically connected to said detonator and to said insulated terminals, said pair of conductors being coiled within said cavity in a manner to permit uncoiling when the drill stem is separated from the bit, rotating means above, and mechanically coupled to, said drill stem, and means for pulling said drill stem from the earth.

CHARLES H. CARLISLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,263,661 Grant et al Apr. 23, 1918 1,517,556 Grant Dec. 2, 1924 1,621,689 Sheldon Mar. 22, 1927 1,905,497 Peters Feb. 5, 1932 1,958,041 Hansen July 21, 1932 2,007,666 Smith Oct. 14, 1933 2,265,982 Bolton Nov. 6, 1939 2,507,230 Stinnett Jan. 21, 11944 FOREIGN PATENTS Number Country Date 28,030 Great Britain Dec. 13, 1911 160,865 Great Britain Apr. '7, 1921 

